Hydrogen is an important raw material in the chemical and petroleum industries. Large quantities are used in the manufacture of ammonia and methanol and in a variety of petroleum hydrotreating processes.
Making hydrogen from methane is of particular interest because in the future hydrogen will be used for the generation of electric power by employing highly efficient fuel cells. While methane is the principal component of natural gas and may be plentiful, it can also be produced by hydrogasification of coal.
Currently, the primary method for converting methane and other light hydrocarbons to produce hydrogen is based on steam reforming. The steam methane reforming (SMR) process often involves multiple steps and severe operating conditions, including high temperatures and pressures.
A proposed method for improving the efficiency of steam methane reforming (SMR) is the Sorption Enhanced Reaction Process (SERP). The SERP method uses a fixed packed bed of an admixture of an SMR catalyst and a chemisorbent to remove carbon dioxide selectively from the reaction zone. The SERP process allows for the use of lower temperatures then those utilized in conventional SMR methods, and provides a higher degree of purity of the resulting hydrogen product.
Within the last few years, the concept of combining reaction and separation steps to simplify various chemical processes, conserve energy, and/or to improve product quality and yield has become economically attractive. Reactive distillation is one method that has been recently commercialized, along with the membrane reactors. Membrane-based reaction systems may involve the use of metallic membranes which only small molecules like hydrogen can permeate, or polymeric, ceramic, and zeolitic membranes. The membranes may act as permselective barriers, or as an integral part of the catalytically active surface.
The present inventors have now discovered a unique method of producing hydrogen through the reaction of steam with methane, other light hydrocarbons, or carbon monoxide using a catalyst and sorbent combined in the same pelletized material. The method is unique compared to presently available technology in that it does not require the catalytic reforming and product separation steps to be conducted with different materials in completely separate steps.
It is therefore a primary objective of the claimed invention to provide a material that is capable of converting methane, other light hydrocarbons, or carbon monoxide to hydrogen and at the same time separate the hydrogen from carbon dioxide co-product.
It is a further objective of the present invention to provide a one-step method of producing hydrogen through the conversion of methane, other light hydrocarbons, or carbon monoxide using a singular material.
It is a further objective of the present invention to provide a material that is regenerable.
It is a further objective of the present invention to provide a material that includes a catalyst to enhance and promote the conversion of methane to hydrogen.
It is yet a further objective of the present invention to provide a material that is durable and attrition resistant.
It is still a further objective of the present invention to provide a material that is economical to manufacture and use.
These and other objectives will become apparent after review of the following description and claims of the invention which follow.